Obama also shared a funny snapshot, taken from a State of the Union address, that might perfectly sum up the pair's relationship: Biden is laughing behind Obama as the former president is delivering his speech with a serious expression on his face.

Joe Biden and Barack Obama in the White House in 2015. Evan Vucci / AP

Earlier this month, Biden appeared on TODAY and shared stories about bonding with Obama over their children and grandchildren — and basketball, since the former president once coached the team that both Biden's granddaughter and Obama's daughter played on. Obama was also there for Biden when his late son, Beau, was battling brain cancer, the former vice president revealed.

"He's a generous guy, he's a genuine guy and (former first lady) Michelle is an incredible lady," Biden said.